US6579621B1 - Moisture barrier film - Google Patents

Moisture barrier film Download PDF

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Publication number
US6579621B1
US6579621B1 US08430632 US43063295A US6579621B1 US 6579621 B1 US6579621 B1 US 6579621B1 US 08430632 US08430632 US 08430632 US 43063295 A US43063295 A US 43063295A US 6579621 B1 US6579621 B1 US 6579621B1
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film
pp
copolymer
epc
layer
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US08430632
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Gautam P. Shah
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Cryovac Inc
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Cryovac Inc
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/06Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/30Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/304Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/30Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/306Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/32Layered products comprising a layer of synthetic resin comprising polyolefins
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/34Layered products comprising a layer of synthetic resin comprising polyamides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/36Layered products comprising a layer of synthetic resin comprising polyesters
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B38/00Ancillary operations in connection with laminating processes
    • B32B38/0012Mechanical treatment, e.g. roughening, deforming, stretching
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00Layered products characterised by the relation between layers, i.e. products comprising layers having different physical properties and products characterised by the interconnection of layers
    • B32B7/04Layered products characterised by the relation between layers, i.e. products comprising layers having different physical properties and products characterised by the interconnection of layers characterised by the connection of layers
    • B32B7/12Layered products characterised by the relation between layers, i.e. products comprising layers having different physical properties and products characterised by the interconnection of layers characterised by the connection of layers using an adhesive, i.e. any interposed material having adhesive or bonding properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2995/00Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0018Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent, phosphorescent
    • B29K2995/0022Bright, glossy, shiny surface
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
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    • B32B38/00Ancillary operations in connection with laminating processes
    • B32B38/0012Mechanical treatment, e.g. roughening, deforming, stretching
    • B32B2038/0028Stretching, elongating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2270/00Resin or rubber layer containing a blend of at least two different polymers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00Properties of the layers or laminate
    • B32B2307/50Properties of the layers or laminate having particular mechanical properties
    • B32B2307/514Oriented
    • B32B2307/518Oriented bi-axially
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00Properties of the layers or laminate
    • B32B2307/70Other properties
    • B32B2307/718Weight, e.g. weight per square meter
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00Properties of the layers or laminate
    • B32B2307/70Other properties
    • B32B2307/724Permeability to gases, adsorption
    • B32B2307/7242Non-permeable
    • B32B2307/7244Oxygen barrier
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
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    • B32B2307/00Properties of the layers or laminate
    • B32B2307/70Other properties
    • B32B2307/726Permeability to liquids, absorption
    • B32B2307/7265Non-permeable
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00Containers; Receptacles
    • B32B2439/70Food packaging
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00Containers; Receptacles
    • B32B2439/80Medical packaging
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    • Y10S428/91Product with molecular orientation
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/1328Shrinkable or shrunk [e.g., due to heat, solvent, volatile agent, restraint removal, etc.]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/1331Single layer [continuous layer]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/1334Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
    • Y10T428/1341Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/1359Three or more layers [continuous layer]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract

A multiple layer film useful in moisture barrier packaging applications has at least one layer comprising a blend of propylene polymer or copolymer, and a hydrocarbon resin; and two additional layers comprising a propylene polymer or copolymer, ethylene alpha olefin copolymer, ionomer, polybutene, or blends thereof. A core layer of ethylene vinyl alcohol copolymer or other oxygen barrier material, or high density polyethylene, can be included in some embodiments. A preferred embodiment of the multi-layer film exhibits excellent moisture barrier and optical properties, and shrink properties as well if the film has been oriented. High oxygen barrier is also a feature in embodiments including EVOH or other oxygen barrier materials.

Description

This is a Divisional application of application Ser. No. 08/358,121, filed Dec. 16, 1994 U.S. Pat. No. 5,543,223, which is a Divisional application of application Ser. No. 08/116,798 filed Sep. 10, 1993 U.S. Pat. No. 5,482,771, which is a Continuation-In-Part of application Ser. No. 07/947,244 filed Sep. 18, 1992 abandoned.

FIELD OF THE INVENTION

This invention relates to thermoplastic films for packaging; and more particularly, this invention relates to a multi-layer film having high moisture barrier characteristics.

BACKGROUND OF THE INVENTION

Thermoplastic film, and in particular polyolefin materials, have been used for some time in connection with packaging of various articles including food products which require protection from the environment, an attractive appearance, and resistance to abuse caring the storage and distribution cycle. Suitable optical properties are also desirable in order to provide for inspection of the packaged product after packaging, in the distribution chain, and ultimately at point of sale. Optical properties such as high gloss, high clarity, and low haze characteristics contribute to an aesthetically attractive packaging material and packaged product to enhance the consumer appeal of the product.

Various polymeric materials have been used to provide lower moisture permeability in order to reduce the transmission of moisture through the packaging film and thereby extend the shelf life of products such as food, medical, electronic, and other items which are sensitive to moisture gain or loss. For some products, maintenance of a high moisture content is desirable, and the film ideally minimizes loss of moisture from the package to the environment. For other products, maintenance of a low moisture content is desirable, and the film ideally minimizes gain of moisture from the environment through the packaging material.

It is also often desirable to include in a packaging film a shrink feature, i.e, the propensity of the film upon exposure to heat to shrink or, if restrained, create shrink tension within the packaging film. This property is imparted to the film by orientation of the film during its manufacture. Typically, the manufactured film is heated to its orientation temperature and stretched in either a longitudinal (machine) or transverse direction (i.e. monoaxial orientation), or both directions (i.e. biaxial orientation), in varying degrees to impart a certain degree of shrinkability in the film upon subsequent heating. When biaxial orientation is done, it can be simultaneous or sequential; that is, the orientation can be done in each of the directions in turn, or else both the longitudinal and transverse orientation can be done at the same time. Any suitable technique, such as blown bubble or tenterframing, can be used to achieve orientation of the film. After being so stretched, the film is rapidly cooled to provide this latent shrinkability to the resulting film. One advantage of shrinkable film is the tight, smooth appearance of the wrapped product that results, providing an aesthetic package as well as protecting the packaged product from environmental abuse. Various food and non-food items may be and have been packaged in shrinkable films.

It is sometimes also desirable to orient a packaging film and thereafter heat set the film by bringing the film to a temperature near its orientation temperature. This produces a film with substantially less shrinkability, while retaining much of the advantages of orientation, including improved tensile strength, modulus and optical properties.

It is an object of the present invention to provide a thermoplastic multilayer film characterized by good moisture barrier properties.

It is a further object of the present invention to provide a thermoplastic multilayer film having an aesthetic appearance with good clarity, and other desirable optical properties.

It is another object of the present invention to provide a thin thermoplastic multilayer film having toughness and abrasion resistance.

It is still another object of the present invention to provide a thermoplastic multilayer film which may be totally coextruded, oriented, and have good moisture barrier and, in some cases, both moisture barrier and oxygen barrier properties.

Of interest are U.S. Pat. No. 4,921,749 (Bossaert et al); U.S. Pat. No. 5,085,943 (Crighten et al); U.S. Pat. No. 5,091,237 (Schloegel et al); U.S. Pat. No. 5,128,183 (Buzio); and U.S. Pat. No. 5,212,009 (Peiffer et al) disclosing the use of hydrocarbon resins.

SUMMARY OF THE INVENTION

The present invention relates to a thermoplastic multi-layer film comprising a core layer comprising a blend of propylene polymer or copolymer, or ethylene alpha olefin copolymer, and a hydrocarbon resin; and two outer layers comprising a propylene polymer or copolymer, ethylene alpha olefin copolymer, polybutene, or blends thereof.

In another aspect, the present invention relates to a thermoplastic multi-layer film comprising a core layer comprising a blend of propylene polymer or copolymer, and a hydrocarbon resin; two intermediate layers, on opposite surfaces of the core layer, comprising propylene polymer or copolymer, or a polymeric adhesive; and two outer layers comprising a propylene polymer or copolymer, ethylene alpha olefin copolymer, ionomer, polybutene, or blends thereof.

The present invention also relates to a thermoplastic multi-layer film comprising a core layer comprising an ethylene alpha olefin copolymer, ethylene propylene copolymer, rubber modified ethylene propylene copolymer, or ethyene propylene butane terpolymer; two intermediate layers, on opposite surfaces of the core layer, comprising a blend of propylene polymer or copolymer, and a hydrocarbon resin; and two outer layers comprising a propylene polymer or copolymer, ethylene alpha olefin copolymer, ionomer, polybutene, or blends thereof.

A film with oxygen barrier as well as moisture barrier properties comprises a core layer comprising an oxygen barrier material; two intermediate layers, on opposite surfaces of the core layer, comprising a polymeric adhesive; two outer layers comprising a blend of propylene polymer or copolymer, or polybutene, and a hydrocarbon resin; and a polymeric sealant layer adhered to at least one of the outer layers.

An alternative film with at least seven layers comprises a core layer comprising high density polyethylene; two intermediate layers, on opposite surfaces of the core layer, comprising a polymeric adhesive, ethylene vinyl acetate copolymer, or ethylene alpha olefin copolymer; two outer layers comprising a blend of propylene polymer or copolymer, and a hydrocarbon resin; and two outermost layers comprising propylene polymer or copolymer, polybutene, or blends thereof.

Another alternative is a film comprising a core layer comprising an oxygen barrier material; two intermediate layers, on opposite surfaces of the core layer, comprising polyamide; two tie layers, each disposed on a respective polyamide layer, comprising a polymeric adhesive, ethylene alpha olefin copolymer, or ethylene vinyl acetate copolymer; two moisture barrier layers, adhered to respective adhesive layers, comprising a blend of propylene polymer or copolymer, and a hydrocarbon resin; and two outermost layers comprising a propylene polymer, propylene copolymer, ethylene alpha olefin copolymer, or polybutene.

In another aspect of the invention, a method of making a thermoplastic multilayer film comprises the steps of coextruding an interior layer of a blend of propylene polymer or copolymer, and a hydrocarbon resin, and two outer layers comprising a propylene polymer or copolymer, ethylene alpha olefin copolymer, polybutene, or blends thereof; cooling the coextruded multilayer film; and collapsing the cooled film.

DEFINITIONS

“Hydrocarbon resin” (“HC” herein) and the like as used herein means resins made by the polymerization of monomers imposed of carbon and hydrogen only. Thermoplastic resins of low molecular weight made from relatively impure monomers derived from coal-tar fractions, petroleum distillates, etc. are also included. A discussion of HC resins can be found e.g. in U.S. Pat. No. 4,921,749 (Bossaert et al); U.S. Pat. No. 5,091,237 (Schloegel et al); and U.S. Pat. No. 5,128,183 (Buzio).

“Ethylene alpha olefin copolymer” (EAO) is used here to include such materials as linear low density polyethylene (LLDPE); very low and ultra low density polyethylene (VLDPE and ULDPE); and metallocene catalyzed polymers such as those supplied by Exxon. Tafmer (tm) materials supplied by Mitsui are also included. These materials generally include copolymers of ethylene with one or more comonomers selected from C4 to C20 alphaolefins such as butene-1, hexene-1, octene-1, etc. in which the molecules of the copolymers comprise long chains with relatively few side chain branches or cross-linked structures. This molecular structure is to be contrasted with conventional low or medium density polyethylenes which are more highly branched than their respective counterparts. “LLDPE” as defined here has a density in the range of from about 0.916 grams per cubic centimeter to about 0.940 grams per cubic centimeter. Generally, “EAO” as used here includes both homogeneous and heterogeneous polymers. “Intermediate layer” and the like is used herein to define a layer in a multi-layer film enclosed on both sides by other layers, i.e. disposed between other layers of the film.

The term “oriented” and the like is used herein to define a polymeric material in which the molecules have been aligned in the longitudinal and/or transverse direction by a process such as a tenter frame or blown bubble process.

“Propylene polymer” and the like is used here to mean polymerized propylene in its homopolymer form, and “propylene copolymers” means copolymers such as ethyene propylene copolymer, where generally small amounts of a comonomer such as ethylene are included in the copolymer. Terpolymers are also included.

“Polymeric adhesive” and the like here means polymeric materials, of any suitable composition, which can be used to create or enhance interlaminar bonds in multilayer thermoplastic films. Polyolefins are preferred, especially those which have been modified, e.g. by carboxylic acid or acid anhydride in a graft copolymer.

“Rubber modified as EPC” and the like here means an EPC which has been modified by the inclusion of other moieties in the polymer structure. Such material may provide improved elasticity or other properties. An example is believed to be Himont KS-052 P, or those available from Rexene (El Paso).

“Ethylene propylene butene terpolymer” and the like is used here to mean a terpolymer incorporating these three comonomers in various percentages. An example is KT-021 from Himont, or those available from Sumitomo.

“Core layer” as used herein means an intermediate layer of a multilayer film, and the central layer where the film has an odd number of layers.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details are given below with reference to the drawing figures wherein

FIG. 1 is a schematic cross section of a preferred embodiment of a multi-layer moisture barrier film of the invention, and

FIGS. 2 and 3 are alternative embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring specifically to the drawings, in FIG. 1, a schematic cross section of a preferred embodiment of the multi-layer moisture barrier film of the invention is shown. The multi-layer film 10 has the generalized structure of A/B/A where A is an outer layer, and B is a core layer comprising a moisture barrier material.

Core layer 12 preferably comprises a blend of a propylene polymer or copolymer, and a hydrocarbon resin, this blend shown as a spotted/striped layer. A typical example of a propylene homopolymer is Exxon PD 4062 E7, or those available from Fina, or Himont PD 064. A preferred propylene copolymer is ethylene propylene copolymer sold under the designation Fina 8473 or Fina 8473X. This material has an ethylene content of about 4%. A preferred hydrocarbon resin is Regalrez 1128 or 1139 from Hercules. The HC resin preferably comprises between about 30% and 50% by weight of the blend.

Outer layers 14 and 16 are preferably ethylene propylene copolymer (EPC), polypropylene (PP), or blends thereof. If only polypropylene resin is used, the film can be difficult to use for packaging applications involving heat sealing. Therefore, it is preferable to use EPC alone, or the blend of the two materials. Commercial resin examples are those discussed above for core layer 12. An alternative polypropylene for the outer layers 14 and 16 is Himont PDO 64. These blend layers may include from 0-100% EPC and 100%-0% PP, although preferably the blend layers include between about 96% and 85% EPC and between about 4% and 15% PP; even more preferably, the blend layer includes about 92% EPC and 8% PP. EAO and polybutene can also be used in the outer layers.

In FIG. 2, a schematic cross section of another embodiment of the multi-layer moisture barrier film of the invention is generally shown. The multi-layer film has the structure of A/B/C/B/A where A is an outer layer, B is an intermediate adhesive layer, and C is a core layer comprising a moisture barrier material.

The core layer preferably comprises a blend of a propylene polymer or copolymer, and a hydrocarbon resin. Suitable materials are those described above for core layer 12 of film 10.

The outer layers are preferably the materials discussed above for outer layers 14 and 16 of film 10. The outer layers also preferably include an HC such as described for core layer 12 of film 10.

The intermediate layers preferably comprise a propylene polymer or copolymer, or blends thereof, optionally blended with hydrocarbon resin.

An alternative A/B/C/B/A structure is also within the scope of this invention, and specifically shown by the position of the moisture barrier layers in the film of FIG. 2.

In this alternative, core layer 24 preferably comprises an ethylene alpha olefin copolymer, more preferably a linear EAO. Very low density polyethylene (VLDPE), and linear low density polyethyene (LLDPE) are preferred. A suitable LLDPE is Dowlex 2045. The core layer 24 can also comprise EPC, a rubber modified EPC, or an ethylene terpolymer, especially an ethylene propylene butene terpolymer such as KT 021 P from Himont.

Outer layers 20 and 28 are preferably the materials discussed above for outer layers 14 and 16 of film 10.

Intermediate layers 22 and 26 preferably comprise a blend of a propylene polymer or copolymer, and a hydrocarbon resin. Suitable materials are those described above for core layer 12 of film 10. An alternative material for layers 22 and 26 is Exxon 6042, which is believed to be a blend of polypropylene and hydrocarbon resin.

In FIG. 3, a schematic cross section of another embodiment of the multi-layer moisture barrier film of the invention is shown. The multi-layer film 30 has the generalized structure of A/B/C/D/C/B/A where A is an outer layer, B is a moisture barrier layer, C is an intermediate adhesive layer, and D is a core layer comprising an oxygen barrier material.

Core layer 38 preferably comprises an oxygen barrier material such as ethylene vinyl alcohol copolymer, vinylidene chloride copolymer, polyester, or polyamide.

Outer layers 32 and 44 are preferably the materials discussed above for outer layers 14 and 16 of film 10.

Intermediate layers 36 and 40 preferably comprise a propylene polymer or copolymer, such as Exxon PD 4062 E7. Alternative materials are polymeric adhesives, especially carboxylic acid or maleic anhydride-modified polyolefins and more preferably polypropylene-based carboxylic acid or maleic anhydride-modified adhesives. Conventional lamination or other suitable methods may sometimes be necessary, depending on the nature of the respective layers, to ensure adequate interlaminar bond strength.

Moisture barrier layers 34 and 42 preferably comprise a blend of a propylene polymer or copolymer, and a hydrocarbon resin. Suitable materials are those described above for core layer 12 of film 10. An alternative material for layers 34 and 42 is Exxon 6042.

An alternative film with at least seven layers comprises a core layer 38 comprising high density polyethylene; two intermediate layers 36 and 40, on opposite respective surfaces of the core layer, comprising a polymeric adhesive, ethylene vinyl acetate copolymer, or ethylene alpha olefin copolymer; two moisture barrier layers 34 and 42 comprising a blend of propylene polymer or copolymer and a hydrocarbon resin; and two outermost layers 32 and 44 comprising propylene polymer or copolymer.

A multilayer film of four or six layers, and/or possessing both moisture barrier and oxygen barrier properties, can also be made in accordance with the present invention. In such alternative constructions, a blend of HC resin with propylene polymer or copolymer can be present in any of the layers of the multilayer film.

The core, intermediate, and moisture barrier layers of such a film can be like that of film 30. A sealant layer is coextruded with, or extrusion coated, extrusion laminated, or adhesive laminated, by means and methods well known in the art, to one of the moisture barrier layers. The sealant layer, which can be disposed on one or both outer surfaces of the film structure, preferably comprises an ethylene alpha olefin copolymer, more preferably a linear EAO. Very low density polyethylene (VLDPE), and linear low density polyethyene (LLDPE) are preferred. A suitable LLDPE is Dowlex 2045. The sealant Layer can also comprise EPC, a rubber modified EPC, an ethylene propylene butene terpolymer such as KT 021 P from Himont, an ethylene vinyl acetate copolymer, an ethylene alkyl acrylate copolymer, an ethylene acrylic or methacrylic acid copolymer, or an ionomer.

The films of the present invention can be made by coextrusion, extrusion coating, extrusion laminating, and conventional adhesive lamination techniques well known in the art, using annular or slot die extrusion equipment as appropriate.

The beneficial low moisture transmission rates (high moisture barrier) and other properties associated with exemplary films of the present invention are demonstrated in the Tables.

The resins used in these examples are identified in Table 1, and the films made from these resins are identified in Tables 2 through 8.

Physical properties of these films are itemized in the remaining Tables. Values given are typically average values obtained from four replicate measurements; values for MVTR are average obtained from three samples.

The terms and abbreviations In the Tables have the following meaning:

“PP”=polypropylene.

“EPC”=ethylene propylene copolymer.

“EAC”=ethylene alpha olefin copolymer.

“EPB”=ethylene propylene butene terpolymer.

“EVOH”=ethylene vinyl alcohol copolymer.

“ADH”=polymeric adhesive; ADH 1 is an ethylene butene-based adhesive from Du Pont; ADH 2 is an EPC-based adhesive from Mitsui.

“AB”=antiblock.

“MO”=mineral oil.

“Tensile”=tensile at break and 73° F., in PSI (ASTM D 882-81).

“PSI”=pounds per square inch (ASTM 882-81).

“Unshrunk”=a film sample or samples that were not shrunk by exposure to heat at the time of testing for the stated property.

“Shrunk”=a film sample or samples that were shrunk by exposure to heat at the time of testing for the stated property.

“LD”=longitudinal orientation direction.

“TD”=transverse orientation direction.

“Modulus”=modulus of elasticity (ASTM 882-81) in PSI at 73° F.

“Haze”=haze (ASTM D 1003-61 (reapproved 1977)) in percent.

“Clarity”=total light transmission (ASTM D 1003 Method A) in percent.

“Gloss”=gloss measured at 45° angle to film surface (ASTM D 2457-70 (reapproved 1977)).

“MVTR 1”=moisture (water) vapor transmission rate (ASTM F 372) in grams/24 hours, 100 square inches at 100% relative humidity and 100° F.

“MVTR 2”=moisture (water) vapor transmission rate (ASTM F 372) in grams/24 hours, 100 square inches at 90% relative humidity and 100° F.

“OTR”=oxygen transmission rate (ASTM D 3985-81) in cc at standard temperature and pressure, in 24 hours, per square meter, at one atmosphere, at 0% relative humidity.

“Teat”=tear propagation in grams at 73° F. (ASTM D 1938-79).

“Film Thickness”=the average thickness (gauge) of the film samples in mils (=0.001 inches).

“Tensile”=tensile strength at break (ASTM D 882-81) in psi.

“Elongation”=elongation at break (ASTM D 882-81) in percent.

“Ball Burst”=ball burst impact in centimeters-kilograms at 73° F. (ASTM D 3420-80).

TABLE 1
MATERIAL TRADENAME SUPPLIER
PP 1 Profax PD-064 Himont
PP 2* [see footnote]
PP 3 PD 4062 Exxon
PP 4** Escorene PD 6042 Exxon
[see footnote]
EPC 1 Fina 8473 or Fina
Fina 8473 X
EPC 2*** [see footnote]
EPC 3 PD 9302 Exxon
EPB 1 KT-021 Himont
HC 1 Regalrez 1128 Hercules
HC 2 Escorez 5340 Exxon
HC 3 Regalrez 1139 Hercules
EAO 1 Dowlex 2045.03 Dow
EAO 2 Dowlex 2045.04 Dow
ADH 1 Bynel CXA 4104 Du Pont
ADH 2 Admer QF 551 A Mitsui
EVOH 1 EVAL SC H-103 Evalca
EVOH 2 EVAL LC F-101 A Evalca
EVOH 3 EVAL LC H-103 Evalca
MO 1 Kaydol Witco
*PP 2 is a masterbatch blend of PP 1 with about 4%, by weight of the blend, of a silica-containing anti-blocking agent, about 5% by weight of amide waxes, and about 1% of a lubricating agent. The amide waxws and lubricating agent are well known in the art as slip agents.
**PP 4 is Escorene PD 6042, believed to be a blend of polypropylene and hydrocarbon resin.
***EPC 2 is a blend of EPC 1 blended with about 1.5%, by weight of the blend, of an antiblock agent, and 0.5%, by weight of the blend, of a mineral oil.

TABLE 2 (CONTROL)

Initial efforts to make a moisture carrier material involved the use of homopolymer polypropylene in a core layer, with sealant layers of propylene copolymer on both surfaces of he core layer. The object was to maximize thickness of the core layer to minimize the moisture vapor transmission rate (MVTR), while still maintaining adequate free shrink and sealability properties of the film. The MVTR did not prove adequate for at least some moisture barrier packaging applications. An example of this film is given below:

EXAMPLE FILM STRUCTURE
1. 92% EPC 1 + 8% PP 2/PP 1/92% EPC 1 + 8% PP 2
The generalized structure of the film of
Example 3 was A/B/A.
Relative layer thickness ratios:
A = 1.0; B = 2.0; A = 1.0

TABLE 3

The films of Table 3 were made in an effort to make a moisture barrier material with tower MVTR. This was achieved using hydrocarbon resin blended with homopolymer polypropylene. It was found that these formulations had much lower moisture vapor transmission rate (MVTR) than those of Table 2. However, they could not be oriented much over 4.5×4.5 racking (orientation) ratio because of equipment limitations. On other equipment, e.g. a modified bubble process or tenterframing, higher orientation (racking) rates can be achieved. They also could not be made into heavier gauge films because of relatively poor tear properties. Examples of these films are given below:

EXAMPLE FILM STRUCTURE
2. 90%[92% EPC 1 + 8% PP 2] + 10% HC 1
PP 3
84.5% PP 3 + 15% HC 1 + 0.5% MO 1
PP 3
90%[92% EPC 1 + 8% PP 2] + 10% HC 1
The generalized structure of the film of Example 2 was
A/B/C/B/A.
Relative layer thickness ratios:
2.5:0.8:3.7:0.6:2.4.
3. 92% EPC 1 + 8% PP 2/PP 4/92% EPC 1 + 8% PP 2
The generalized structure of the film of Example 3 was
A/B/A.
Relative layer thickness ratios:
1:2:1
4. 92% EPC 1 + 8% PP 2/PP 4/92% EPC 1 + 8% PP 2
The generalized structure of the film of Example 4 was
A/B/A.
Relative layer thickness ratios:
1:3:1.

TABLE 4

Alternative films of Table 4 were made in which, in effect, the core layer of the films of Table 3 (i.e. the layer containing the hydrocarbon resin) were “split” into two substrate (intermediate) layers. A “new” core layer of e.g. LLDPE or EPC is introduced. The practical effect of this is to improve tear properties of the film, related to tape creasing during the orientation process, so that it can be oriented at e.g. 6×6 ratio. The film was in fact oriented at 4×4.5 because of the equipment limitations discussed for the Examples of Table 3. Examples of these films are given below:

EXAMPLE FILM STRUCTURE
5. 92% EPC 1 + 8% PP 2/PP 4/EAO 1/PP 4/92%
EPC 1 + 8% PP 2
The generalized structure of the film of
Example 5 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
6. 92% EPC 1 + 8% PP 2/PP 4/EPC 1/PP 4/92%
EPC 1 + 8% PP 2
The generalized structure of the film of
Example 6 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5

TABLE 5

The inventor took the basic constructions of Table 4, and oriented them at generally higher racking ratios of 6×6. The result was a film showing improvements in (i.e. lower) MVTR. Examples of these films are given below:

EXAMPLE FILM STRUCTURE
7. 92% EPC 1 + 8% PP 2/PP 4/EAO 1/PP 4/92%
EPC 1 + 8% PP 2
The generalized structure of the film
of Example 7 was A/B/C/B/A. This film was
like that of Example 5, but with both
MD and TD racking ratios of about 6 × 6 in
the longitudinal and transverse
directions respectively.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
8. 92% EPC 1 + 8% PP 2/PP 4/EAO 1/PP 4/92%
EPC 1 + 8% PP 2
The generalized structure of the film
of Example 8 was A/B/C/B/A. This film was
like that of Example 7, but oriented
at a higher temperature compared to
Example 7.
Relative layer thickness ratios:
1.5:3:1:3:1.5
9. 92% EPC 1 + 8% PP 2/PP 4/EAO 2/PP 4/92%
EPC 1 + 8% PP 2
The generalized structure of the film
of Example 9 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
10. 92% EPC 1 + 8% PP 2/PP 4/EPB 1/PP 4/92%
EPC 1 + 8% PP 2
The generalized structure of the film
of Example 10 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
11. 92% EPC 1 + 8% PP 2
70% PP 3 + 30% HC 2
EAO 2
70% PP 3 + 30% HC 2
92% EPC 1 + 8% PP 2
The generalized structure of the film
of Example 11 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
12. 90% EPC 1 + 10% PP 2/PP 4/EPC 1/PP 4/90%
EPC 1 + 10% PP 2
The generalized structure of the film
of Example 12 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
13. 90% EPC 1 + 10% PP 2/PP 4/EPC 1/PP 4/90%
EPC 1 + 10% PP 2
The generalized structure of the film
of Example 13 was A/B/C/B/A. This film was
like that of Example 12, but lower racking
ratios of 4.5 × 4.5 to produce a film
of 132 gauge thickness.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
14. 90% EPC 1 + 10% PP 2/PP 4/EPC 1/PP 4/90%
EPC 1 + 10% PP 2
The generalized structure of the film
of Example 14 was A/B/C/B/A. This film was
like that of Example 13, but with slightly
higher racking ratios (4.5 × 5.0) and
a final film thickness of 155 gauge.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
15. 87.5% EPC 3 + 12.5% PP 2
PP 4
EPC 3
PP 4
87.5% EPC 3 + 12.5% PP 2
The generalized structure of the film
of Example 15 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
16. 84% EPC 3 + 16% PP 2
PP 4
EPC 3
PP 4
84% EPC 3 + 16% PP 2
The generalized structure of the film
of Example 16 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.
17. 86% EPC 3 + 14% PP 2
PP 4
EPC 3
PP 4
86% EPC 3 + 14% PP 2
The generalized structure of the film
of Example 17 was A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5.

TABLE 6

The inventor made a seven layer film (Example 18) as a control, and then made two moisture/oxygen barrier seven-layer films (Examples 19 and 20) with good results. Examples of these films are given below:

EXAMPLE FILM STRUCTURE
18. 92% EPC 1 + 8% PP 2
PP 3
ADH 2
EVOH 1
ADH 2
PP 3
92% EPC 1 + 8% PP 2
The generalized structure of the film of
Example 18 was A/B/C/D/C/B/A.
Relative layer thickness ratios:
1:2.5:1:1:1:2.5.:1
19. 92% EPC 1 + 8% PP 2
PP 4
ADH 1
EVOH 2
ADH 1
PP 4
92% EPC 1 + 8% PP 2
The generalized structure of the film of
Example 19 was A/B/C/D/C/B/A.
Relative layer thickness ratios:
1.5:2:1:1:1:2:1.5
20. 92% EPC 1 + 8% PP 2
PP 4
ADH 2
EVOH 3
ADH 2
PP 4
92% EPC 1 + 8% PP 2
The generalized structure of the film of
Example 20 was A/B/C/D/C/B/A.
Relative layer thickness ratios:
1.5:2:1:1:1:2:1.5

TABLE 7

Two alternative films of seven layers have the structure:

21. 92% EPC 1+ 8% PP 2
PP 4
EVA 1
HDPE 1
EVA 1
PP 4
92% EPC 1 + 8% PP 2
The generalized structure of the film of
Example 21 is A/B/C/D/C/B/A.
Relative layer thickness ratios:
1:2.5:1:1:1:2.5:1
22. 92% EPC 1+ 8% PP 2
PP 4
VLDPE 1
HDPE 1
VLDPE 1
PP 4
92% EPC 1 + 8% PP 2
The generalized structure of the film of
Example 22 is A/B/C/D/C/B/A.
Relative layer thickness ratios:
1:2.5:1:1:1:2.5:1

TABLE 8

Two additional alternative films of five layers were made, and are compared in Table 13 with the film of Example 17. These two additional films have the following structures:

23. 86% EPC 3+ 14% PP 2
PP 4
85% EPC 3+ 15% HC 3
PP 4
86% EPC 3+ 14% PP 2
The generalized structure of the film of
Example 23 is A/B/C/B/A.
Relative layer thickness ratios:
1.5:3:1:3:1.5
24. 86% [85% EPC 3+ 15% HC 3] + 14% PP 2
PP 4
85% EPC 3+ 15% HC 3
PP 4
85% EPC 3+ 15% HC 3
The generalized structure of the film of
Example 24 is A/B/C/B/C.
Relative layer thickness ratios:
1.5:3:1:3:1.5

TABLE 9
Example 1
(control) Example 2 Example 3 Example 4
Modulus
LD 239,480 279,920 316,030 336,820
TD 214,690 260,240 298,930 316,820
Free Shrink/Shrink Tension
at 220° F.:
LD 7/396 9/321 10/315 11/408
TD 12/388 14/381 17/528 17/504
at 220° F.:
LD 12/435 14/335 14/361 15/439
TD 18/432 19/383 24/540 25/548
at 240° F.:
LD 18/451 20/364 20/443 22/494
TD 26/469 28/413 33/591 33/516
at 260° F.:
LD 31/473 31/397 33/429 33/511
TD 35/493 39/441 45/538 44/561
Haze
Unshrunk 1.2 1.7 1.3 1.3
Shrunk 1.6 2.3 3.2 2.1
Clarity
Unshrunk 81 87 87 88
Shrunk 80 84 83 87
Gloss
87 84 87 88
Film Thickness (mils)
(related to MVTR data given below)
Unshrunk 0.96 0.80 0.77 0.75
Actual
MVTR 1
Unshrunk 0.60 0.67 0.60 0.55
Corrected 0.77 0.71 0.62 0.55
for 75 gauge
MVTR 2
Unshrunk 0.49 0.55 0.48 0.45
Corrected 0.63 0.59 0.49 0.45
for 75 gauge

TABLE 10
Example 7 Example 8 Example 9 Example 10
Modulus
LD 271,200 299,200
TD 292,100 337,900
Free Shrink
at 220° F.:
LD 13 13
TD 19 20
at 240° F.:
LD 20 17 20 18
TD 28 23 30 27
at 260° F.:
LD 27 28
TD 37 38
Haze
Unshrunk 1.7 1.8
Clarity
Unshrunk 82 84
Gloss
84 85
Film Thickness (mils)
(related to MVTR data given below)
Unshrunk 0.86 0.76 0.86 0.77
Shrunk 1.00 0.97
MVTR 1
Unshrunk 0.51 0.56
Shrunk 0.41 0.46
Corrected
for 75 gauge
Unshrunk 0.58 0.57
Shrunk 0.55 0.59
MVTR 2
Unshrunk 0.45 0.47 0.42 0.43
Shrunk 0.35 0.38
Corrected
for 75 gauge
Unshrunk 0.52 0.48 0.48 0.44
Shrunk 0.47 0.49
Tear (grams)
LD 8.6 5.0
TD 8.4 6.1

TABLE 11
Example 11 Example 12 Example 13 Example 14
Modulus
LD 345,750 352,880 322,950 320,470
TD 374,990 392,020 334,660 319,420
Free Shrink
at 240° F.:
LD 20 17 18 14
TD 29 23 24 25
Haze
Unshrunk 48.5 1.3 3.3 5.3
Clarity
Unshrunk 21 85 74 64
Gloss
107 89 73 64
Film Thickness (mils)
(related to MVTR data given below)
Unshrunk 0.85 0.81 1.40 1.60
MVTR 2
Unshrunk 0.36 0.36 0.23 0.19
Corrected 0.41 0.39 0.43 0.41
for 75 gauge
Tear (grams)
LD 8.6 5.0
TD 8.4 6.1

TABLE 12
Example 19 Example 20
Modulus
LD 300,890 307,380
TD 315,460 291,480
Free Shrink/Shrink Tension
at 220° F.:
LD 8/440 14/395
TD 19/632 20/595
at 240° F.:
LD 18/477 21/439
TD 28/654 27/611
at 260° F.:
LD 28/446 29/436
TD 38/621 35/601
at 280° F.:
LD 44/467 43/487
TD 52/600 46/587
at 300° F.:
LD 59/— 60/—
TD 62/— 61/—
Haze
Unshrink 1.6 1.8
Clarity
Unshrunk 76 76
Gloss
89 86
Film Thickness (mils)
(related to MVTR data given below)
Unshrunk 1.09 1.12
MVTR 2
Non-shrunk 0.35 0.33
Corrected 0.51 0.49
for 75 gauge
Tear
LD 6 6
TD 6 7
Tensile
LD 19,415 20,407
TD 19,296 16,990
Elongation
LD 63 62
TD 71 77
Ball Burst
12 11
OTR
3.0 4.5

TABLE 13
Example 17 Example 23 Example 24
Modulus
LD 398,000 420,000 437,000
TD 442,000 473,000 488,000
Free Shrink
at 220° F.:
LD 15 14 15
TD 19 19 22
at 240° F.:
LD 20 19 19
TD 26 26 28
at 260° F.:
LD 30 30 26
TD 38 36 38
at 280° F.:
LD 44 44 44
TD 51 51 52
at 300° F.:
LD 64 63 62
TD 68 67 68
Haze
Unshrunk 1.8 2.0 1.2
Clarity
Unshrunk 82 81 81
Gloss
86 83 89
Film Thickness (mils)
(related to MVTR data given below)
Unshrunk 0.89 0.91 0.82
MVTR 2
Unshrunk 0.33 0.36 0.33
Corrected 0.39 0.44 0.36
for 75 gauge
Tear
LD 1 7 4
TD 5 7 6
Tensile
LD 28,000 31,000 28,000
TD 29,000 33,000 29,000
Elongation
LD 80 86 84
TD 71 52 73

In a typical working example of making the film of the present invention:

An ethylene propylene copolymer (Fina 8473) containing about 4% by weight ethylene, was blended with the polypropylene in a blend ratio or about 92% by weight EPC and 8% by weight PP. (The PP percentage includes the additives discussed above).

The EPC/PP blend was then blended with a hydrocarbon resin (Regalrez 1128 from Hercules) in a blend ratio of about 90% by weight EPC/PP and 10% by weight HC.

A second blend was also prepared, in a blend ratio of about 84.5% by weight PP (Exxon PD 4062 E7), 15% by weight HC (Regalrez 1128), and 0.5% white mineral oil (Kaydol from Witco Chemical).

A circular coextrusion die was fed with three extruders to prepare a five layer shrink film. One extruder was used to feed the blend of EPC or polypropylene, and HC, as a melt to the extrusion die to form the outer layers. Another extruder fed a polypropylene (Exxon PD 4062 E7) to the extrusion die to provide the intermediate layers in the multi-layer film. The third extruder provided the second blend of PP and HC to the extrusion die.

The extruded tape was rapidly cooled to room temperature and collapsed by pinch rolls. The tape was subsequently heated to an orientation temperature. Using a bubble technique well known in the art, internal air pressure stretched the tape to about 4.5 times its unstretched dimensions in the longitudinal (machine) direction and about 4.0 times its unstretched dimensions in the transverse direction to form a bubble which provided biaxial orientation to the resulting film. The bubble was then rapidly cooled by chilled air in order to maintain the oriented state of the film. Finally, the bubble was collapsed and the expanded film gathered on a take-up roll. After orientation, the total wall thickness of the film was about one mil with 50% of the structure being the blend of ethylene propylene copolymer and polypropylene; 15% of the structure being the intermediate layers; and the remainder or 35% of the structure being the core layer.

It will be clear to one skilled in the arc that the degree of stretching may be varied to obtain the desired degree of film gauge or thickness and to regulate the desired amount of shrink tension, free shrink, and other shrink properties of the final film, depending on the packaging application. Preferred stretching or racking ratios are between about 3.0 and 8.0 in both the machine and transverse directions.

The multi-layer film of the present invention is preferably not irradiated. However, the sealant material, if extrusion laminated, extrusion coated, or conventionally laminated to the substrate moisture barrier film, can itself be irradiated or electronically or chemically crosslinked prior to lamination. Irradiation ray be accomplished by means well known in the art.

The blend ratios of the EPC and PP may be varied according to desired properties or end-use of the multi-layer film. For example, increasing the polypropylene in the blend will add stiffness to the film, but also increase the sealing temperature of the film. Conversely, increasing the EPC in the blend tends to lower the shrink temperature of the oriented film, or to increase shrink at the same temperature, and also lowers the sealing temperature of the film. A preferred blend includes between about 4% and 15% PP and between about 96% and 85% EPC.

The multilayer film of the present invention is preferably oriented either monoaxially or biaxially, and preferably used as a shrink film. Optionally, the oriented film may be further processed by reheating the film to a temperature near its orientation temperature, i.e. either somewhat below, at, or somewhat about its orientation temperature, to heat set the film. This future processing stem has the advantage of substantially retaining many of the favorable physical characteristics of an oriented film, such as higher tensile strength, modulus and improved optical properties, while providing a substantial shrink-free film in applications where a shrink feature is undesirable.

The film of the present invention can utilize hydrocarbon resin in at least one or more, or even all the layers of the film, as long as the HC resin in any given layer is compatible from a process and performance point of view with the resin with which it is blended.

Films in accordance with this invention are preferably oriented, and preferably heat shrinkable. Preferred films exhibit a free shrink at 240° F. of at least 10% (LD) and 15% (TD), more preferably at least 15% (LD) and 22% (TD).

Obvious modifications to the invention as described may be made by one skilled in the art without departing from the spirit and scope of the claims as presented below.

Claims (3)

What is claimed is:
1. A thermoplastic multi-layer film comprising:
a) a core layer comprising an oxygen barrier material;
b) two intermediate layers, on opposite surfaces of the core layer, comprising a polymeric adhesive;
c) two outer layers comprising a blend of propylene polymer or copolymer, and a hydrocarbon resin, wherein the hydrocarbon resin comprises a thermoplastic resin of low molecular weight made from relatively impure monomers that are derived from coal-tar fractions or petroleum distillates; and
d) a polymeric sealant layer adhered to at least one of the outer layers;
wherein the film is heat shrinkable.
2. The film of claim 1 wherein the oxygen barrier layer comprises a polymeric material selected from the group consisting of:
i) ethylene vinyl alcohol copolymer,
ii) vinylidene chloride copolymer,
iii) polyester, and
iv) polyamide.
3. The film of claim 1 wherein the sealant layer comprises a polymeric material selected from the group consisting of:
i) propylene polymer,
ii) propylene copolymer,
iii) ethylene alpha olefin copolymer,
iv) ionomer,
v) polybutene, and
vi) blends thereof.
US08430632 1992-09-18 1995-04-28 Moisture barrier film Expired - Fee Related US6579621B1 (en)

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US08358121 US5543223A (en) 1992-09-18 1994-12-16 Moisture barrier film
US08430632 US6579621B1 (en) 1992-09-18 1995-04-28 Moisture barrier film

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Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020164470A1 (en) * 2001-02-22 2002-11-07 Bader Michael J. Multi-layer hermetically sealable film
US20040016208A1 (en) * 2002-07-23 2004-01-29 Mumpower Edward L. Package including a lidstock laminate
US20040175464A1 (en) * 2003-03-07 2004-09-09 Blemberg Robert J. Multilayer structures, packages, and methods of making multilayer structures
US20040173491A1 (en) * 2003-03-07 2004-09-09 Buelow Duane H. Packages made from thermoplastic multilayer barrier structures
US20040173932A1 (en) * 2003-03-07 2004-09-09 Douglas Michael J. Methods of making multilayer structures
US20040175466A1 (en) * 2003-03-07 2004-09-09 Douglas Michael J. Multilayer barrier structures, methods of making the same and packages made therefrom
US20040175465A1 (en) * 2003-03-07 2004-09-09 Buelow Duane H. Thermoplastic multilayer structures
US20040175592A1 (en) * 2003-03-07 2004-09-09 Douglas Michael J. Thermoplastic multilayer barrier structures
US20040175467A1 (en) * 2003-03-07 2004-09-09 Mueller Chad D. Packages made from multilayer structures
US20040173944A1 (en) * 2003-03-07 2004-09-09 Mueller Chad D. Methods of making multilayer barrier structures
US20060194054A1 (en) * 2003-04-11 2006-08-31 Treofan Germany Gmbh & Company Co. Biaxially oriented polypropylene film with cold sealing adhesive
EP1728816A2 (en) 2005-06-01 2006-12-06 Cryovac, Inc. Method of activating the shrink characteristic of a film
US20070036999A1 (en) * 2005-08-15 2007-02-15 Rogers Agent Rhonda E Coated polymeric films and coating solutions for use with polymeric films
WO2007062391A2 (en) * 2005-11-22 2007-05-31 Triton Systems, Inc. Multilayer flame retardant barrier films and fabrics
US20090061057A1 (en) * 2007-08-28 2009-03-05 Cryovac, Inc. Multilayer Film Having an Active Oxygen Barrier Layer With Radiation Enhanced Active Barrier Properties
US20090061061A1 (en) * 2007-08-28 2009-03-05 Cryovac, Inc. Multilayer Film Having Passive and Active Oxygen Barrier Layers
US20090084787A1 (en) * 2005-07-14 2009-04-02 Tetra Laval Holdings & Finance S.A. Packaging Containers, Method of Producing Innertape, and Innertape for Packaging Containers
US20100015423A1 (en) * 2008-07-18 2010-01-21 Schaefer Suzanne E Polyamide structures for the packaging of moisture containing products
US20100239796A1 (en) * 2009-03-23 2010-09-23 Gagne Joseph Donald Lap sealable laminate and packaging made therefrom
US7857515B2 (en) 2007-06-15 2010-12-28 S.C. Johnson Home Storage, Inc. Airtight closure mechanism for a reclosable pouch
US7874731B2 (en) 2007-06-15 2011-01-25 S.C. Johnson Home Storage, Inc. Valve for a recloseable container
US7887238B2 (en) 2007-06-15 2011-02-15 S.C. Johnson Home Storage, Inc. Flow channels for a pouch
US7946766B2 (en) 2007-06-15 2011-05-24 S.C. Johnson & Son, Inc. Offset closure mechanism for a reclosable pouch
US7967509B2 (en) 2007-06-15 2011-06-28 S.C. Johnson & Son, Inc. Pouch with a valve
US8741433B2 (en) 2004-12-10 2014-06-03 Curwood, Inc. Packaging films comprising nylon blend compositions
WO2017112886A1 (en) * 2015-12-23 2017-06-29 Coveris Holding Corp. Multi-layer films and methods of manufacturing the same
US9907726B2 (en) 2014-04-03 2018-03-06 Kewpie Kabushiki Kaisha Injection bag and injection preparation assembly

Families Citing this family (67)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995006556A1 (en) * 1993-09-02 1995-03-09 Quantum Chemical Corporation Biaxially-oriented polypropylene film with improved gas barrier
ES2193191T3 (en) * 1993-09-02 2003-11-01 Applied Extrusion Technologies Biaxially oriented polypropylene films.
DE4404041C1 (en) * 1994-02-09 1995-03-23 Ruesch Willy Ag Polymer material of medical instruments and process for preparing the polymer material
DE4419709A1 (en) * 1994-06-06 1995-12-07 Wolff Walsrode Ag Impermeable, highly transparent and puncture resistant composite film
DE69426490D1 (en) * 1994-09-07 2001-02-01 Cryovac Inc Chlorine-free composite film material, process for its preparation and its use
JP3273293B2 (en) * 1994-12-27 2002-04-08 コニカ株式会社 Photographic light-sensitive material for the polymer resin packaging material
US5738923A (en) * 1995-05-16 1998-04-14 Minnesota Mining And Manufacturing Company Medical tubing and assemblies
EP0744285B1 (en) * 1995-05-24 1999-12-15 Cryovac, Inc. Multilayer oxygen barrier packaging film
US5814413A (en) * 1995-06-07 1998-09-29 Huntsman United Films Corporation Multilayer protective garment film
DE59602125D1 (en) 1995-11-04 1999-07-08 Tetra Laval Holdings & Finance Paper-like and thermoformable multilayer barrier films
JPH09183198A (en) * 1995-11-16 1997-07-15 Soten Srl Heat-shrinkable co-extrusion-molded multilayered polyolefin film with improved seal heat resistance
US5677044A (en) * 1995-12-18 1997-10-14 Montell Technology Company Bv Multilayer thermoshrinkable films
US5976682A (en) * 1996-03-12 1999-11-02 Tenneco Packaging Stretch wrap films
USRE38429E1 (en) * 1996-03-12 2004-02-17 Tyco Plastics Services Ag Stretch wrap films
US5998017A (en) * 1996-03-12 1999-12-07 Tenneco Packaging Stretch wrap films
US5902684A (en) * 1996-03-12 1999-05-11 Tenneco Packaging Inc. Multilayered Metallocene stretch wrap films
FR2751941B1 (en) * 1996-08-02 1998-09-11 Oreal A device for separate packaging of two components, mixing and dispensing the mixture thus obtained
US5888648A (en) * 1996-09-12 1999-03-30 Mobil Oil Corporation Multi-layer hermetically sealable film and method of making same
US6086967A (en) * 1996-11-06 2000-07-11 The Dow Chemical Company Modified atmosphere films useful in the packaging of perishable food
EP0850756A3 (en) * 1996-12-25 1999-02-03 Japan Polychem Corporation Container and sheet of propylene polymer laminate
US5989725A (en) * 1997-01-16 1999-11-23 Tenneco Packaging Clear high molecular weight film
US6013378A (en) * 1997-03-17 2000-01-11 Tenneco Packaging HMW HDPE film with improved impact strength
US5907942A (en) * 1997-05-21 1999-06-01 Tenneco Packaging Stretch wrap films
US6093480A (en) * 1997-05-21 2000-07-25 Tenneco Packaging Stretch wrap films
US5907943A (en) * 1997-06-11 1999-06-01 Tenneco Packaging Inc. Stretch wrap films
US5922441A (en) * 1997-06-11 1999-07-13 Tenneco Packaging Inc. Stretch wrap films
US6017615A (en) * 1997-08-25 2000-01-25 Huntsman Polymers Corporation Film product comprising novel polyolefins
US6083611A (en) * 1997-11-12 2000-07-04 Tenneco Packaging, Inc. Roll wrap film
US5994045A (en) * 1997-12-24 1999-11-30 Eastman Kodak Company Composite photographic material with laminated biaxially oriented polyolefin sheets with controlled water vapor transmission rate
CA2350764C (en) 1998-12-18 2004-04-27 Cryovac, Inc. Highly bi-axially oriented, heat-shrinkable, thermoplastic, multi-layer film and process for the manufacture thereof
DE60000176D1 (en) * 1999-01-15 2002-06-27 Unilever Plc Wrappings for piece soaps
US6336553B1 (en) 1999-06-07 2002-01-08 Colgate-Palmolive Company Soap wrappers
US6455161B1 (en) 1999-06-30 2002-09-24 Dow Global Technologies Inc. Essentially amorphous, non-chlorinated polymeric barrier films and method of using such films
US6458469B1 (en) * 1999-07-08 2002-10-01 Exxonmobil Chemical Company Multilayer oriented films with metallocene catalyzed polyethylene skin layer
EP1108531B1 (en) * 1999-12-17 2004-07-28 Shin-Etsu Polymer Co., Ltd. Laminated plastic film for food wrapping
US6440533B1 (en) 2000-09-22 2002-08-27 Tredegar Film Products Corporation PVC replacement film
US6531214B2 (en) 2001-02-14 2003-03-11 3M Innovative Properties Company Replacement for plasticized polyvinyl chloride
US6531212B2 (en) 2001-02-14 2003-03-11 3M Innovative Properties Company Retroreflective article and method
US7077935B2 (en) * 2001-05-04 2006-07-18 General Atomics O2 and H2O barrier material
US20030211350A1 (en) * 2002-05-10 2003-11-13 Migliorini Robert A. Multilayer heat sealable polyolefin film comprising skin layer and transition layer of differing melting points
US6905760B1 (en) * 2002-08-29 2005-06-14 Asahi Kasei Life And Living Corporation Polypropylene-based wrap film
EP1464480B1 (en) 2003-03-31 2005-09-28 Tohcello Co., Ltd. Gas barrier laminated film and a process for producing same
JP4359850B2 (en) 2003-04-03 2009-11-11 株式会社プライムポリマー Packaging films
US20050137342A1 (en) * 2003-12-19 2005-06-23 Krishnaswamy Rajendra K. Polyethylene blend films
US20050145138A1 (en) * 2003-12-30 2005-07-07 Council Of Scientific And Industrial Research Oxygen barrier material for packaging
WO2006031172A1 (en) * 2004-09-13 2006-03-23 Tetra Laval Holdings & Finance S.A. A strip tape, a packaging container having such a strip tape, and a method of producing such a strip tape
US7732027B2 (en) 2004-11-29 2010-06-08 Toray Advanced Film Co., Ltd. Polypropylene film and laminated material thereof
US7279206B2 (en) * 2005-03-22 2007-10-09 Curwood, Inc. Packaging laminates and articles made therefrom
US7829147B2 (en) 2005-08-18 2010-11-09 Corning Incorporated Hermetically sealing a device without a heat treating step and the resulting hermetically sealed device
US7722929B2 (en) 2005-08-18 2010-05-25 Corning Incorporated Sealing technique for decreasing the time it takes to hermetically seal a device and the resulting hermetically sealed device
US20070040501A1 (en) 2005-08-18 2007-02-22 Aitken Bruce G Method for inhibiting oxygen and moisture degradation of a device and the resulting device
KR20090091705A (en) * 2006-11-21 2009-08-28 피나 테크놀러지, 인코포레이티드 Polyethylene useful for producing film and molded articles in a process which uses solid state stretching
US8115326B2 (en) 2006-11-30 2012-02-14 Corning Incorporated Flexible substrates having a thin-film barrier
US20080286547A1 (en) * 2007-05-18 2008-11-20 Hubbard Michael A Polypropylene films with enhanced moisture barrier properties, process for making and composition thereof
US20090286090A1 (en) * 2008-05-19 2009-11-19 Ting Yuan-Ping R Enhance performance on current renewable film using functional polymer coatings
EP2141016A1 (en) 2008-07-01 2010-01-06 Dow Global Technologies Inc. Films, articles prepared therefrom and methods of making the same
EP2145763A1 (en) 2008-07-16 2010-01-20 Dow Global Technologies Inc. Films, articles prepared therefrom, and method of making the same
JP5563665B2 (en) 2009-11-06 2014-07-30 ホリスター インコーポレイティド Multilayer films and concrete 瘻製 products made therefrom
US8225927B2 (en) * 2009-11-13 2012-07-24 Applied Materials, Inc. Method to substantially enhance shelf life of hygroscopic components and to improve nano-manufacturing process tool availablity
KR20120130285A (en) * 2010-02-12 2012-11-29 가부시키가이샤 벨 폴리에스테르 프로덕츠 Material for forming packaging body, packaging body, product, and method for preventing adsorption
DE102011017404A1 (en) * 2011-04-18 2012-10-18 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. A process for depositing a transparent barrier layer system
US9265648B2 (en) 2012-05-15 2016-02-23 Hollister Incorporated Odor barrier film
US8658560B1 (en) 2012-10-15 2014-02-25 Heesung Catalysts Corporation Hydrogenation catalyst for nitro-aromatic compounds and method for preparing the same
US20150298437A1 (en) * 2012-11-28 2015-10-22 Dow Global Technologies Llc Microlayer Component for Films with Improved Gas/Moisture Carrier by Controlling Crystal Lamellae Orientation
US20140264167A1 (en) * 2013-03-15 2014-09-18 Multisorb Technologies, Inc. Water vapor barrier composition
KR20140127629A (en) 2013-04-25 2014-11-04 삼성디스플레이 주식회사 Functional polarizing film and organic luminescence emitting display device employing the same
EP3102410B1 (en) * 2014-02-06 2018-07-18 Imballaggi Protettivi S.r.l. Sandwich sheet or panel made of thermoplastic material

Citations (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4230767A (en) 1978-02-08 1980-10-28 Toyo Boseki Kabushiki Kaisha Heat sealable laminated propylene polymer packaging material
US4343852A (en) 1979-07-13 1982-08-10 Toyo Boseki Kabushiki Kaisha Composite film and packaging material of polypropylene base and surface polymer composition
US4386187A (en) * 1980-06-11 1983-05-31 Sweetheart Plastics, Inc. Thermoformable polymer blend composition comprising styrene polymer, olefin polymer and block copolymer
US4390385A (en) 1980-05-23 1983-06-28 W. R. Grace & Co., Cryovac Div. Heat sealable, multi-ply polypropylene film
US4439478A (en) 1980-05-23 1984-03-27 W. R. Grace & Co., Cryovac Division Heat sealable, multi-ply polypropylene film
EP0137454A2 (en) 1983-10-07 1985-04-17 Asahi Kasei Kogyo Kabushiki Kaisha Highly-oriented stretchable multilayer film and process for producing the same
EP0180087A2 (en) 1984-10-23 1986-05-07 Hoechst Aktiengesellschaft Coextruded multilayer and biaxially stretched opaque polyolefine sheet with mechanical properties
US4681797A (en) * 1984-09-26 1987-07-21 Cobelplast N.V.S.A. Thermoformable, multi-layer plastic sheet having gas barrier properties
EP0118060B1 (en) 1983-02-23 1987-08-19 Hoechst Aktiengesellschaft Multilayered sheet with a layer impermeable to gases and aromas, process for its production and its use
US4724185A (en) * 1985-09-17 1988-02-09 W. R. Grace & Co., Cryovac Div. Oxygen barrier oriented film
US4734318A (en) 1985-11-13 1988-03-29 Hoechst Aktiengesellschaft Multilayer packaging film having superior scratch resistance
US4755419A (en) 1986-03-21 1988-07-05 W. R. Grace & Co., Cryovac Div. Oxygen barrier oriented shrink film
EP0321843A2 (en) 1987-12-23 1989-06-28 Hoechst Aktiengesellschaft Opaque multi-layer film with inherent resistance to delamination
US4869938A (en) 1986-08-22 1989-09-26 Mitsui Toatsu Chemicals Inc. Polypropylene sheet for press-through packages, production process thereof, and polypropylene resin composition
US4886690A (en) * 1987-12-21 1989-12-12 W. R. Grace & Co. Peelable barrier film for vacuum skin packages and the like
US4921749A (en) 1986-05-30 1990-05-01 Exxon Chemical Patents Inc. Sealable films
US4948657A (en) 1987-03-09 1990-08-14 Sumitomo Chemical Company, Limited Multi-layer shrink film
EP0415270A2 (en) 1989-08-29 1991-03-06 Chisso Corporation Opaque, laminated and stretched products and method for making them
US5043204A (en) 1987-11-30 1991-08-27 Toa Nenryo Kogyo Kabushiki Kaisha Oriented polyethylene film
US5075156A (en) 1988-03-15 1991-12-24 Asahi Kasei Kogyo Kabushiki Kaisha Multi-layered crosslinked ethylenic resin film, a process for production thereof and a method of applying said film
US5085943A (en) 1987-11-16 1992-02-04 Courtaulds Films & Packaging (Holdings) Ltd. Polypropylene films
US5091237A (en) 1988-06-25 1992-02-25 Hoechst Aktiengesellschaft Transparent shrink film based on polypropylene, process for its manufacture, and its use for shrink labels
JPH0477235A (en) 1990-07-18 1992-03-11 Honshu Paper Co Ltd Heat-shrinkable polypropylene film
US5116926A (en) 1990-05-04 1992-05-26 Imperial Chemical Industries Plc Polyolefin film
US5118566A (en) 1989-06-29 1992-06-02 Hoechst Aktiengesellschaft Biaxially-oriented polypropylene film with high mechanical strength
US5128183A (en) 1990-08-01 1992-07-07 Borden, Inc. Modified polyolefin film with stable twist retention, dead fold properties and barrier characteristics
US5132074A (en) 1989-04-10 1992-07-21 Kohjin Co., Ltd. Process of making stretchable, heat shrinkable polyethylene film
US5145728A (en) 1987-11-30 1992-09-08 Toa Nenryo Kogyo Kabushiki Kaisha Oriented polyethylene film
US5151317A (en) 1989-12-05 1992-09-29 Hoechst Aktiengesellschaft Biaxially-oriented polyolefin multi-layer film which can be sealed on both sides, and the preparation and use of the same
JPH04275143A (en) 1990-12-06 1992-09-30 Hoechst Ag Biaxially oriented multilayered polyolefin film sealable on both sides with enhanced shrinkage and improved barrier characteristic
US5152946A (en) 1991-01-30 1992-10-06 Hercules Incorporated Producing low shrink packaging film
US5185203A (en) 1988-11-15 1993-02-09 Tonen Sekiyukagaku K.K. Heat-sealable crosslinked oriented polyethylene film and production thereof
US5204182A (en) 1990-05-04 1993-04-20 Imperial Chemical Industries Plc Polyolefin film
US5212009A (en) 1989-05-31 1993-05-18 Hoechst Aktiengesellschaft Multi-layer transparent polyolefin film for application in shrink labelling
US5213744A (en) 1987-04-21 1993-05-25 Exxon Chemical Patents Inc. Process for making polyolefin films
US5234733A (en) 1988-05-03 1993-08-10 Hoechst Aktiengesellschaft Heat-sealable shrink film based on polypropylene
US5292563A (en) 1990-11-24 1994-03-08 Hoechst Aktiengesellschaft Metallizable, twist wrap, biaxially oriented, polypropylene film
US5318829A (en) * 1992-03-13 1994-06-07 Okura Industrial Co., Ltd. Heat shrinkable laminate film
US5429862A (en) 1990-07-21 1995-07-04 Hoechst Aktiengesellschaft Biaxially oriented sealable polypropylene film having improved barrier properties
EP0492720B1 (en) 1990-12-24 1996-02-14 POLIFILMS S.r.l. Heat-shrinking, multi layer films based on olefinic resins also containing non-olefinic resins

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4615926A (en) * 1984-07-20 1986-10-07 American Can Company Film and package having strong seals and a modified ply-separation opening
US4726984A (en) * 1985-06-28 1988-02-23 W. R. Grace & Co. Oxygen barrier oriented film
GB8709446D0 (en) * 1987-04-21 1987-05-28 Exxon Chemical Patents Inc Polyolefine films
CA1340240C (en) * 1988-09-21 1998-12-15 W.R. Grace & Co.-Conn. Coextruded film with peelable sealant
DE69018606D1 (en) * 1990-02-01 1995-05-18 Borden Inc Film of modified polyolefin with stable Eindrehverhalten, folding properties and blocking characteristic.
DE4030385A1 (en) * 1990-09-26 1992-04-02 Hoechst Ag Transparent shrink film of biaxially oriented polypropylene for the all-around labeling
US5110677A (en) * 1990-10-01 1992-05-05 W. R. Grace & Co.-Conn. Lettuce packaging film
US5295563A (en) * 1993-03-01 1994-03-22 General Motors Corporation Active suspension actuator with control flow through the piston rod

Patent Citations (42)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4230767A (en) 1978-02-08 1980-10-28 Toyo Boseki Kabushiki Kaisha Heat sealable laminated propylene polymer packaging material
US4343852A (en) 1979-07-13 1982-08-10 Toyo Boseki Kabushiki Kaisha Composite film and packaging material of polypropylene base and surface polymer composition
US4390385A (en) 1980-05-23 1983-06-28 W. R. Grace & Co., Cryovac Div. Heat sealable, multi-ply polypropylene film
US4439478A (en) 1980-05-23 1984-03-27 W. R. Grace & Co., Cryovac Division Heat sealable, multi-ply polypropylene film
US4386187A (en) * 1980-06-11 1983-05-31 Sweetheart Plastics, Inc. Thermoformable polymer blend composition comprising styrene polymer, olefin polymer and block copolymer
EP0118060B1 (en) 1983-02-23 1987-08-19 Hoechst Aktiengesellschaft Multilayered sheet with a layer impermeable to gases and aromas, process for its production and its use
EP0137454A2 (en) 1983-10-07 1985-04-17 Asahi Kasei Kogyo Kabushiki Kaisha Highly-oriented stretchable multilayer film and process for producing the same
US4681797A (en) * 1984-09-26 1987-07-21 Cobelplast N.V.S.A. Thermoformable, multi-layer plastic sheet having gas barrier properties
EP0180087A2 (en) 1984-10-23 1986-05-07 Hoechst Aktiengesellschaft Coextruded multilayer and biaxially stretched opaque polyolefine sheet with mechanical properties
US4724185A (en) * 1985-09-17 1988-02-09 W. R. Grace & Co., Cryovac Div. Oxygen barrier oriented film
US4734318A (en) 1985-11-13 1988-03-29 Hoechst Aktiengesellschaft Multilayer packaging film having superior scratch resistance
US4755419A (en) 1986-03-21 1988-07-05 W. R. Grace & Co., Cryovac Div. Oxygen barrier oriented shrink film
US4921749C1 (en) 1986-05-30 2001-02-27 Exxon Chemical Patents Inc Sealable films
US4921749A (en) 1986-05-30 1990-05-01 Exxon Chemical Patents Inc. Sealable films
US4869938A (en) 1986-08-22 1989-09-26 Mitsui Toatsu Chemicals Inc. Polypropylene sheet for press-through packages, production process thereof, and polypropylene resin composition
US4948657A (en) 1987-03-09 1990-08-14 Sumitomo Chemical Company, Limited Multi-layer shrink film
US5213744A (en) 1987-04-21 1993-05-25 Exxon Chemical Patents Inc. Process for making polyolefin films
US5085943A (en) 1987-11-16 1992-02-04 Courtaulds Films & Packaging (Holdings) Ltd. Polypropylene films
US5145728A (en) 1987-11-30 1992-09-08 Toa Nenryo Kogyo Kabushiki Kaisha Oriented polyethylene film
US5043204A (en) 1987-11-30 1991-08-27 Toa Nenryo Kogyo Kabushiki Kaisha Oriented polyethylene film
US4886690A (en) * 1987-12-21 1989-12-12 W. R. Grace & Co. Peelable barrier film for vacuum skin packages and the like
EP0321843A2 (en) 1987-12-23 1989-06-28 Hoechst Aktiengesellschaft Opaque multi-layer film with inherent resistance to delamination
US5026592A (en) 1987-12-23 1991-06-25 Hoechst Aktiengesellschaft Opaque multilayered film having an inherent resistance to delamination
US5075156A (en) 1988-03-15 1991-12-24 Asahi Kasei Kogyo Kabushiki Kaisha Multi-layered crosslinked ethylenic resin film, a process for production thereof and a method of applying said film
US5234733A (en) 1988-05-03 1993-08-10 Hoechst Aktiengesellschaft Heat-sealable shrink film based on polypropylene
US5091237A (en) 1988-06-25 1992-02-25 Hoechst Aktiengesellschaft Transparent shrink film based on polypropylene, process for its manufacture, and its use for shrink labels
US5185203A (en) 1988-11-15 1993-02-09 Tonen Sekiyukagaku K.K. Heat-sealable crosslinked oriented polyethylene film and production thereof
US5132074A (en) 1989-04-10 1992-07-21 Kohjin Co., Ltd. Process of making stretchable, heat shrinkable polyethylene film
US5212009A (en) 1989-05-31 1993-05-18 Hoechst Aktiengesellschaft Multi-layer transparent polyolefin film for application in shrink labelling
US5118566A (en) 1989-06-29 1992-06-02 Hoechst Aktiengesellschaft Biaxially-oriented polypropylene film with high mechanical strength
EP0415270A2 (en) 1989-08-29 1991-03-06 Chisso Corporation Opaque, laminated and stretched products and method for making them
US5151317A (en) 1989-12-05 1992-09-29 Hoechst Aktiengesellschaft Biaxially-oriented polyolefin multi-layer film which can be sealed on both sides, and the preparation and use of the same
US5116926A (en) 1990-05-04 1992-05-26 Imperial Chemical Industries Plc Polyolefin film
US5204182A (en) 1990-05-04 1993-04-20 Imperial Chemical Industries Plc Polyolefin film
JPH0477235A (en) 1990-07-18 1992-03-11 Honshu Paper Co Ltd Heat-shrinkable polypropylene film
US5429862A (en) 1990-07-21 1995-07-04 Hoechst Aktiengesellschaft Biaxially oriented sealable polypropylene film having improved barrier properties
US5128183A (en) 1990-08-01 1992-07-07 Borden, Inc. Modified polyolefin film with stable twist retention, dead fold properties and barrier characteristics
US5292563A (en) 1990-11-24 1994-03-08 Hoechst Aktiengesellschaft Metallizable, twist wrap, biaxially oriented, polypropylene film
JPH04275143A (en) 1990-12-06 1992-09-30 Hoechst Ag Biaxially oriented multilayered polyolefin film sealable on both sides with enhanced shrinkage and improved barrier characteristic
EP0492720B1 (en) 1990-12-24 1996-02-14 POLIFILMS S.r.l. Heat-shrinking, multi layer films based on olefinic resins also containing non-olefinic resins
US5152946A (en) 1991-01-30 1992-10-06 Hercules Incorporated Producing low shrink packaging film
US5318829A (en) * 1992-03-13 1994-06-07 Okura Industrial Co., Ltd. Heat shrinkable laminate film

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
An Improved Moisture . . . SPO '91, 423-445.
Arkon-A Film and Resin . . . Mitsui Plastics, Inc 1-32.
Escorez Tackifying Resins Polymers/Exxon Chem.
Hydrocarbon Resins Hydrocarbon Resins vol. 7-758-779.
New Resins for Improving. Regalrez 1128/1139.
Whittington's Dictionary . . . 164.

Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020164470A1 (en) * 2001-02-22 2002-11-07 Bader Michael J. Multi-layer hermetically sealable film
US20040016208A1 (en) * 2002-07-23 2004-01-29 Mumpower Edward L. Package including a lidstock laminate
US6769227B2 (en) * 2002-07-23 2004-08-03 Cryovac, Inc. Package including a lidstock laminate
US9498937B2 (en) 2003-03-07 2016-11-22 Coveris Flexibles Us Llc Multilayer structures, packages, and methods of making multilayer structures
US20040173491A1 (en) * 2003-03-07 2004-09-09 Buelow Duane H. Packages made from thermoplastic multilayer barrier structures
US20040173932A1 (en) * 2003-03-07 2004-09-09 Douglas Michael J. Methods of making multilayer structures
US20040175466A1 (en) * 2003-03-07 2004-09-09 Douglas Michael J. Multilayer barrier structures, methods of making the same and packages made therefrom
US20040175465A1 (en) * 2003-03-07 2004-09-09 Buelow Duane H. Thermoplastic multilayer structures
US20040175592A1 (en) * 2003-03-07 2004-09-09 Douglas Michael J. Thermoplastic multilayer barrier structures
US20040175467A1 (en) * 2003-03-07 2004-09-09 Mueller Chad D. Packages made from multilayer structures
US20040175464A1 (en) * 2003-03-07 2004-09-09 Blemberg Robert J. Multilayer structures, packages, and methods of making multilayer structures
US20050118373A1 (en) * 2003-03-07 2005-06-02 Blemberg Robert J. Multilayer structures, packages, and methods of making multilayer structures
US20050118374A1 (en) * 2003-03-07 2005-06-02 Douglas Michael J. Multilayer barrier structures, methods of making the same and packages made therefrom
US9498936B2 (en) 2003-03-07 2016-11-22 Coveris Flexibles Us Llc Multilayer barrier structures, methods of making the same and packages made therefrom
US20040173944A1 (en) * 2003-03-07 2004-09-09 Mueller Chad D. Methods of making multilayer barrier structures
US20060194054A1 (en) * 2003-04-11 2006-08-31 Treofan Germany Gmbh & Company Co. Biaxially oriented polypropylene film with cold sealing adhesive
US8741433B2 (en) 2004-12-10 2014-06-03 Curwood, Inc. Packaging films comprising nylon blend compositions
EP1728816A2 (en) 2005-06-01 2006-12-06 Cryovac, Inc. Method of activating the shrink characteristic of a film
US20090084787A1 (en) * 2005-07-14 2009-04-02 Tetra Laval Holdings & Finance S.A. Packaging Containers, Method of Producing Innertape, and Innertape for Packaging Containers
US20070036999A1 (en) * 2005-08-15 2007-02-15 Rogers Agent Rhonda E Coated polymeric films and coating solutions for use with polymeric films
US7473439B2 (en) 2005-08-15 2009-01-06 Exxonmobil Oil Corporation Coated polymeric films and coating solutions for use with polymeric films
WO2007062391A3 (en) * 2005-11-22 2007-11-29 Triton Systems Inc Multilayer flame retardant barrier films and fabrics
US8784978B2 (en) 2005-11-22 2014-07-22 Triton Systems, Inc. Multilayer flame retardant barrier films and fabrics
WO2007062391A2 (en) * 2005-11-22 2007-05-31 Triton Systems, Inc. Multilayer flame retardant barrier films and fabrics
US20070149678A1 (en) * 2005-11-22 2007-06-28 Shah Apoorva Multilayer flame retardant barrier films and fabrics
US7857515B2 (en) 2007-06-15 2010-12-28 S.C. Johnson Home Storage, Inc. Airtight closure mechanism for a reclosable pouch
US7874731B2 (en) 2007-06-15 2011-01-25 S.C. Johnson Home Storage, Inc. Valve for a recloseable container
US7887238B2 (en) 2007-06-15 2011-02-15 S.C. Johnson Home Storage, Inc. Flow channels for a pouch
US7946766B2 (en) 2007-06-15 2011-05-24 S.C. Johnson & Son, Inc. Offset closure mechanism for a reclosable pouch
US7967509B2 (en) 2007-06-15 2011-06-28 S.C. Johnson & Son, Inc. Pouch with a valve
US8231273B2 (en) 2007-06-15 2012-07-31 S.C. Johnson & Son, Inc. Flow channel profile and a complementary groove for a pouch
US20090061061A1 (en) * 2007-08-28 2009-03-05 Cryovac, Inc. Multilayer Film Having Passive and Active Oxygen Barrier Layers
US20090061057A1 (en) * 2007-08-28 2009-03-05 Cryovac, Inc. Multilayer Film Having an Active Oxygen Barrier Layer With Radiation Enhanced Active Barrier Properties
US8815360B2 (en) 2007-08-28 2014-08-26 Cryovac, Inc. Multilayer film having passive and active oxygen barrier layers
US9452592B2 (en) 2007-08-28 2016-09-27 Cryovac, Inc. Multilayer film having an active oxygen barrier layer with radiation enhanced active barrier properties
US20100015423A1 (en) * 2008-07-18 2010-01-21 Schaefer Suzanne E Polyamide structures for the packaging of moisture containing products
US20100239796A1 (en) * 2009-03-23 2010-09-23 Gagne Joseph Donald Lap sealable laminate and packaging made therefrom
US9907726B2 (en) 2014-04-03 2018-03-06 Kewpie Kabushiki Kaisha Injection bag and injection preparation assembly
WO2017112886A1 (en) * 2015-12-23 2017-06-29 Coveris Holding Corp. Multi-layer films and methods of manufacturing the same

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US5910374A (en) 1999-06-08 grant
JP3342127B2 (en) 2002-11-05 grant
KR960014027B1 (en) 1996-10-11 grant
JPH06198826A (en) 1994-07-19 application
CN1067017C (en) 2001-06-13 grant
EP0588667A2 (en) 1994-03-23 application
CA2106258A1 (en) 1994-03-19 application
CA2106258C (en) 2003-11-04 grant
EP0588667A3 (en) 1994-08-03 application
US5543223A (en) 1996-08-06 grant
CN1084452A (en) 1994-03-30 application

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